The present invention relates to a catheter particularly useful for inducing labor and/or for the application of a pharmaceutical substance to the cervix of the uterus.
It has been shown recently that a certain pharmaceutical substance, namely prostaglandin (PG), leads to local biochemical and biophysical alterations in the cervical region that have the effect of reducing cervical resistance in addition to inducing myometrial contractions. Endocervical application of this substance in a gel has been gaining increasing acceptance for priming the cervix before the induction of labour or for the induction of labour. A pre-manufactured mixture of 0.5 mg PGE.sub.2 and 2.5 mm triacetin gel ("Prepidil Gel", supplied by Upjohn, Crawley) is now available, and recent trials exhibited no gel-specific problems relating to stability, homogeneity or sterility.
At the present time, the Prepidil Gel is applied by intra-cervical injection using a syringe with a simple canula. However, it is extremely difficult, if not impossible, to administer 3 ml of gel in a strictly endocervical fashion without applying some of the gel retroamniotically, and without having some flowing back out of the cervical canal to the vagina.
An object of the present invention is to provide a catheter particularly useful for this purpose.
During clinical studies made with the above-described catheter it was surprisingly discovered that merely the insertion of the catheter without the delivery of the pharmaceutical substance also had the effect in many cases of artificially ripening the cervix and inducing labor.
Accordingly, another object of the present invention is to provide a catheter which may be used for inducing labor by merely inserting the catheter as described above and without the delivery of the phamaceutical substance.
Further objects of the present invention are to provide a method of inducing labor in a female, and also a method of applying a pharmaceutical substance directly to the cervical canal of a female.